Hello EBo, The A20 board has a 3 volt lithium battery on it that will keep the CPU and memory alive for about 20 minutes. The software is setup to shutdown if power is absent for more than 3 minutes. This is really not required because the / filesystem is read only, and the read-write filesystem is XFS. My X86-64 distro takes considerably longer to boot. Both BIOS and the PC hardware scan slow things down considerably, which adds in excess of 30 seconds more to the boot time. Shutdown is about the same on both platforms, at about 4 seconds.
While LOC is a concern (the more parts, the more chances of failure), that is not the driving point. The driving point is bloat. Using a desktop OS to drive a machine is just a bad idea, no matter how you slice it. When you are controlling a machine, reliability is everything. The problem with a desktop OS is that there are many factors that are out of control, especially things like web browsers. There is almost no control of how many CPU cycles, HD access, and memory that a browser uses. Also, they use many features of the graphics system, so if there is a bug in the graphics system, a web browser usually brings it out and in some cases can take out X11. Experience has demonstrated that if you eliminate X11, you eliminate about 90% of the things that randomly crash a machine. That is one major advantage of working with Qt and GTK, you can run the applications straight to the Linux framebuffer and bypass X11 entirely. It is absolutely amazing how more reliable things become when you get rid of all of the bloat that X11 and the window manager add, not to mention all of the things that are not in the path, like a desktop, launcher, file indexers, session servers (session servers are the biggest breaking point of most desktop systems)... -Neil- > > > If you can get it to boot in that amount of time, I would also ask how > much time does it take to properly shutdown. At that point I would set > up a small UPS which has at least 3x the power required to do a proper > shutdown (which I am assuming would be something on the order of 10 > seconds, or 30s for a safety margin, and can probably be done with some > capacitors). Then if someone removed the power on the fly it does not > matter. > > Also, if you are deeply concerned about LOC, then take a look at the > Plan9 OS and its derivatives like Inferno and Plan B. The entire code > base for Plan 9 is ~80,000 LOC for the entire OS. Using the 9P protocol > and similar you should be able to drop the an expected 50% off of the > LOC for your chosen interface and stuff it even further down the eeprom > hole. > > EBo -- > > > ------------------------------------------------------------------------------ > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
